BALTIMORE, MD - JULY 29: Travis Blackley #54 of the Oakland Athletics pitches against the Baltimore Orioles at Oriole Park at Camden Yards on July 29, 2012 in Baltimore, Maryland. (Photo by Greg Fiume/Getty Images)

Photo: Greg Fiume, Getty Images

BALTIMORE, MD - JULY 29: Travis Blackley #54 of the Oakland...

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OAKLAND, CA - AUGUST 02: Brandon Inge #7 of the Oakland Athletics avoids an inside pitch from Henderson Alvarez #37 of the Toronto Blue Jays (not pictured) during the third inning at O.co Coliseum on August 2, 2012 in Oakland, California. (Photo by Jason O. Watson/Getty Images)

Photo: Jason O. Watson, Getty Images

OAKLAND, CA - AUGUST 02: Brandon Inge #7 of the Oakland Athletics...

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OAKLAND, CA - AUGUST 02: Ryan Cook #48 of the Oakland Athletics is congratulated by George Kottaras #14 (left) after the game against the Toronto Blue Jays at O.co Coliseum on August 2, 2012 in Oakland, California. The Oakland Athletics defeated the Toronto Blue Jays 4-1. (Photo by Jason O. Watson/Getty Images)

Photo: Jason O. Watson, Getty Images

OAKLAND, CA - AUGUST 02: Ryan Cook #48 of the Oakland Athletics is...

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OAKLAND, CA - AUGUST 02: Brandon Inge #7 of the Oakland Athletics hits an RBI single against the Toronto Blue Jays during the seventh inning at O.co Coliseum on August 2, 2012 in Oakland, California. The Oakland Athletics defeated the Toronto Blue Jays 4-1.(Photo by Jason O. Watson/Getty Images)

Photo: Jason O. Watson, Getty Images

OAKLAND, CA - AUGUST 02: Brandon Inge #7 of the Oakland Athletics...

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Toronto Blue Jays' Henderson Alvarez raises his cap in the third inning of a baseball game against the Oakland Athletics, Thursday, Aug. 2, 2012, in Oakland, Calif. (AP Photo/Ben Margot)

Photo: Ben Margot, Associated Press

Toronto Blue Jays' Henderson Alvarez raises his cap in the third...

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Oakland Athletics catcher George Kottaras, left, congratulates pitcher Ryan Cook at the end of a baseball game against the Toronto Blue Jays, Thursday, Aug. 2, 2012, in Oakland, Calif. The Athletics won 4-1. (AP Photo/Ben Margot)

The A's assembly line for churning out strike-throwing pitchers has provided another model: Dan Straily, who leads all of pro baseball in strikeouts, will make his major-league debut at the Coliseum on Friday.

Straily, 23, will take the place of left-hander Travis Blackley, who shifts to the bullpen. Blackley has been terrific since being acquired on waivers from the Giants in May, but that's yet another indication of how promising Straily is. He's wedged his way into a rotation that already is among the league's best.

"I think we're all excited to watch him pitch," manager Bob Melvin said. "Look at the numbers, that's certainly indicative. ... Everyone glows about him. Tomorrow will be a big day, a lot of hype, and rightly so."

Straily, much like relievers Sean Doolittle and Ryan Cook and starter A.J. Griffin, is a good story, unheralded going into the season. He was not in big-league camp, like Griffin, and he was a 24th-round pick in 2009 - after pitching as a walk-on at Marshall.

"I never got into the prospect thing, because I never was one," said Straily, who is from Oregon and went to Western Oregon before transferring to Marshall.

While the two drove from Phoenix to Double-A Midland this spring, Straily told Griffin that his goal for the season was to top Griffin's strikeout numbers.

"I'm his muse," Griffin said.

Straily has 175 strikeouts in 138 1/3 minor-league innings, more than major-league strikeout leaders Stephen Strasburg and Justin Verlander. The key, according to scouts and to those in the A's organization, has been Straily's outstanding changeup. Straily said he's also become more fearless - he's hitting corners, rather than nibbling and just missing, and at the behest of Midland coach Craig Lefferts, he now expects to get outs rather than hoping to get them.

Straily also throws a fastball that is usually 91-93 mph, but he tops out at 95 mph. He throws a curveball that has improved in the past year, and he has a good slider.

He has visited the Coliseum before. While living in San Jose and playing in a college league in Berkeley before starting at Marshall, Straily and some teammates hopped on BART and bought $2 Wednesday tickets.

Triple-A Sacramento manager Darren Bush has a talent for misdirection when one of his players gets called up to the big leagues, and he pulled off one of his best with Straily. He asked Straily if he might want to play in the Arizona Fall League, and when Straily said he would, Bush told him that he should make sure to tell A's pitching coach Curt Young about that when he saw him Thursday.

Straily was so stunned, he said, "I honestly don't think I said a word."

Straily was 8-6 overall between Midland and Sacramento with a 2.60 ERA - and a .197 opponents average, including .149 against Triple-A hitters.

Blackley had no problem with moving to a relief role. He started off as the A's long reliever in May and worked his way into a starting role. He said he can make himself more valuable by being able to do both things. "And I get to pitch more often this way," he said.

He's also psyched to see Straily pitch. Blackley said he follows the River Cats' Twitter feed, so he knows all those sparkly numbers.

"It doesn't seem like there's a level yet that can hold him down," Blackley said. "This is the big leagues, but from the sound of it, he shouldn't have too much of an issue."